Use of an attic stair insulating cover can save money by reducing costly energy from escaping through an attic stair opening. Energy savings accrued through the use of an attic stair insulating cover will obviously be offset by the initial cost of the insulating cover. To recover and significantly profit from their initial investment in the insulating cover, the insulating cover must provide effective insulation during use and must also be both durable and relatively cheap. In addition, once placed in an operational position the attic stair insulating cover should be safe to use.
Several factors impact the effectiveness of an insulating cover in preventing loss of energy through the attic opening. The ability to properly position the insulating cover over the attic stair opening after exiting the attic is one important factor in evaluating the effectiveness of the insulating cover. As disclosed U.S. Pat. No. 4,928,441, issued May 29, 1990, mounting the insulating cover into position over the attic stair opening with hinges that are attached to the cover ensures proper positioning of the insulating cover. Attaching a gasket to the insulating cover, as disclosed in U.S. Pat. No. 4,928,441, also improves the insulation characteristics of an insulating cover by providing a seal between the attic floor surface and the insulating cover.
One problem with insulating covers that have attached hinges and gaskets is that such insulating covers are more expensive to produce. To offset the added expense of adding hinges and gaskets, such insulating cover should be durable to extend its effective life. The durability of an insulating cover mounted to the attic stair opening by hinges is limited by stress placed on the cover during use.
When hinges are attached to an insulating cover with fasteners, such as screws, the opening and closing of the insulating cover causes a repeated torque to be produced where the fastener connects to the insulating cover. This repeated torque on the fasteners causes the fasteners to be pulled loose from the insulating cover. In addition, the extreme temperature ranges in attics cause the insulating cover to expand and contract resulting in the fasteners becoming loosen. The combined effects of repeated opening and closing of the insulating cover and the extreme range of temperatures in an attic result in the hinge fasteners being pulled loose from the insulating cover. Once the hinge fasteners are pulled loose, the integrity of the insulating cover is impaired and the hinges may be inoperable.
One approach to improving the durability of the insulating cover is to strengthen the insulating cover such that the attached hinges will not be pulled loose. The problem with increasing the strength of the cover is that strengthening the cover results in a heavier and/or more expensive cover. A heavier cover is also less manageable for a user to position while maintaining a balanced position on attic stairs. Furthermore, a heavier cover is dangerous if the cover happens to fall on the user or the cover slips from the user's grip during the positioning of the cover.
The durability of a gasket attached to a flat bottom edge of the insulating cover is also susceptible to operating conditions of the cover. The extreme temperature range of an attic causes the gasket to repeatedly contract and expand, reducing the effective life of the gasket. Likewise, during opening and closing the section of the gasket located adjacent to the hinges is in particularly stressed. The repeated stress on the gasket, which is typically attached to a flat surface on the bottom edge of a cover, tends to tear the gasket from the insulating cover. In addition, a gasket attached to a flat bottom will have to support the weight of the cover when the cover is placed in a closed position where the cover's bottom edge rests against the attic floor surface. The placement of the cover's weight against the gasket tends to severely wear the gasket. Gaskets attached to a flat bottom edge, as discussed above, have limited durability and must be replaced at regular intervals to maintain the effectiveness of the insulating cover.
As described above, attaching hinges and gaskets to an insulating cover increases the ability of the cover to provide insulation, but the attached hinges and gaskets decrease the durability of these insulating covers. A more durable cover would help a user recoup the greater initial cost of covers having attached hinges and gaskets.
Safety of a person using an insulating cover is an additional concern in producing an effective insulating cover. In particular, the cover should be designed to help prevent the cover from inadvertently falling from an open position to a closed position. The opening and closing of the insulating cover should also be manageable and safe for all users.